Tomas Ojea Quintana, U.N. special rapporteur on the humanrights situation in Myanmar, was speaking at the end of afive-day mission to the country, where President Thein Sein haspushed through reforms since the end of military rule in 2011.

"While this process of reform is continuing in the rightdirection, there are significant human rights shortcomings thatremain unaddressed," Quintana told reporters, calling for urgentaction before the problems became entrenched.

The quasi-civilian government has agreed ceasefires withmost of the ethnic rebel groups fighting for autonomy. Butfighting flared up in Kachin State in June 2011 and the conflictescalated late last year when the military used air strikes tothwart what it said was rebel aggression.

Peace talks were held over the border in China this monthand Quintana said he was encouraged by this. He also welcomedthe government's decision to allow a U.N. humanitarian convoyaccess to areas controlled by the rebels.

But he added: "I am concerned about the ongoing practice ofarbitrary arrest and torture during interrogation by themilitary of Kachin men accused of belonging to the KachinIndependence Army."

Another area, Rakhine State, suffered two bouts of deadlysectarian violence last year between ethnic Rakhine Buddhistsand Muslim Rohingyas.

Around 120,000 people are now living in camps, according toQuintana. Although conditions had improved since his last visitin August, there was still a lack of adequate healthcare in thebigger Muslim camps, he said, adding that harassment of medicalstaff by Rakhine Buddhists was one of the reasons.

The government needed to address the problem of freedom ofmovement in the camps, he said, noting that one "felt more likea prison than a camp".

The government says the Rohingyas are illegal immigrantsfrom Bangladesh and does not regard them as citizens. Bangladeshalso denies them citizenship and the estimated 800,000 inRakhine State are therefore effectively stateless.

Quintana said the two communities remained divided by fear,distrust, anger and hatred.

"Mutually respectful dialogue cannot be had whilediscrimination based on grounds of ethnicity and religionremains unaddressed," he said, recommending that the governmentamend citizenship laws to end such discrimination.